From: Xiaoyao Li <xiaoyao.li@intel.com>

When explicitly booting a multiple vcpus vm with "-cpu +ht", it gets
warning of

  warning: host doesn't support requested feature: CPUID.01H:EDX.ht [bit 28]

Make CPUID_HT as supported unconditionally can resolve the warning.
However it introduces another issue that it also expose CPUID_HT to
guest when "-cpu host/max" with only 1 vcpu. To fix this, need mark
CPUID_HT as the no_autoenable_flags.

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Message-ID: <20231010060539.210258-1-xiaoyao.li@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/cpu.c     | 1 +
 target/i386/kvm/kvm.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 3aab05ddadc..bdca901dfaa 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -778,6 +778,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         },
         .cpuid = {.eax = 1, .reg = R_EDX, },
         .tcg_features = TCG_FEATURES,
+        .no_autoenable_flags = CPUID_HT,
     },
     [FEAT_1_ECX] = {
         .type = CPUID_FEATURE_WORD,
diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f6c7f7e2686..ab72bcdfad1 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -373,6 +373,8 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function,
     if (function == 1 && reg == R_EDX) {
         /* KVM before 2.6.30 misreports the following features */
         ret |= CPUID_MTRR | CPUID_PAT | CPUID_MCE | CPUID_MCA;
+        /* KVM never reports CPUID_HT but QEMU can support when vcpus > 1 */
+        ret |= CPUID_HT;
     } else if (function == 1 && reg == R_ECX) {
         /* We can set the hypervisor flag, even if KVM does not return it on
          * GET_SUPPORTED_CPUID
-- 
2.41.0